2-Distribution of Scores Flashcards
What is a distribution?
The relative frequency with which values of a variable occur in a sample or population.
What is a frequency table?
It conveys the number of scores in a sample or population having each value of a variable.
What is Raw frequency counts (tallies)?
It represent the number of scores in a sample or population having a particular value or falling in a given interval. (f)
What are relative frequencies?
It represent the proportion (p) of scores in a sample or population having a particular value or falling in a given interval.
(frequency of one value divided by the total of frequency)
What is cumulative frequency?
The number of scores at or below a given value of a variable.
What are cumulative proportion?
The proportion of scores at or below a given value of a variable.
What is a percentile rank?
cumulative proportionx100= %
What is the difference between a histogram and a bar graph?
Histograms have :
1) A natural ordering on the x-axis
2) No space between the bars
What is an interval?
A range of values of a quantitative variable.
How do you calculate the range of scores?
Max-min
Interval width depends on what ?
1) The number of intervals we wish to have
2) The range of scores in the data set
What are score limits of an interval?
the minimum and maximum whole values (expressed by whole numbers) of the units of measurement that define the interval.
What are real limits?
the minimum and maximum real values of scores that define the interval.
How do you calculate relative frequency?
The same way you calculate proportion (f/n=proportion or relative frequency)
What is subjective probability?
An individual’s subjective judgment about the likelihood that some event will occur.
What are objective probabilities?
Numerical expressions of the likelihood of some event occurring.
What is the outcome of a sampling experiment?
is the value of the variable that was selected.
What is a sampling experiment ?
the random selection of one of the possible values of a variable.
What is the proportion of success?
is the number of successes divided by the number of sampling experiments,
p = Nsuccess/NSE.
What is an event?
one or more of the possible outcomes of a sampling experiment.
is p = (Nsuccess+Nsuccess)/NSE
What defines the probability of an event?
is the proportion of times the event would occur if the same sampling experiment were repeated INFINITETLY many times.
In probability, what is mutual exclusivity?
Two events that cannot co-occur.
In probability, what is independance?
the occurrence of one event does not affect the probability of the other occurring.
What is probability distribution?
The probability that a randomly selected score will have a given value or fall in a given interval. In other words, shows the proportion of scores falling in any interval.
